Sometimes I wish I'd been a geologist. It would have been fun. Rather dusty and hard on the hands, but fun.

My mind is full of "what ifs" about these rocks from the moon that scientists (geologists?) say came from Earth originally. Well, maybe. They know more than I do. But .......

The moon and Earth were closer together at the time an asteroid blasted them both with flotsam and jetsam. Isn't it possible that both were blasted with the same materials that formed into the same type rock?

Scientists seem to show that all evidence points to an earth-origin. The big argument is our water-rich environment. I ask: The moon has some water now. Did it once have more water? Do they know?

Or should I take my ideas back to a story we were told eons ago? The story - which seems to have died a-borning - was that the moon was blasted from where the Pacific Ocean now is in some planetary collision. Thus, all the same materials on both bodies.

The body that caused the extinction of the dinosaurs has been estimated to have been 6 miles in length. Whether this was a fragment left from the formation of the Earth and Moon or an asteroid that wandered into the inner solar system is debatable, although the high levels of Iridium in the KT (Cretaceous-Tertiary) boundary suggest non-terrestrial origin. It is gratifying to see Dr. Luis Alvarez's work taken seriously.

In 1980, Alvarez, Alvarez, Asaro, and Michel published a seminal paper proposing an extraterrestrial cause for the Cretaceous-Paleogene extinction (then called the Cretaceous-Tertiary extinction).[48]In the years following the publication of their article, the clay was also found to containsoot,glassyspherules,shocked quartzcrystals, microscopicdiamonds, and rare minerals formed only under conditions of great temperature and pressure.[1]

Publication of the 1980 paper brought criticism from the geologic community, and an often acrimonious scientific debate ensued. Ten years later, and after Alvarez's death, evidence of a largeimpact cratercalledChicxulubwas found off the coast of Mexico, providing support for the theory. Other researchers later found that theend-Cretaceous extinctionof the dinosaurs may have occurred rapidly in geologic terms, over thousands of years, rather than millions of years as had previously been supposed. Others continue to study alternative extinction causes such as increasedvolcanism, particularly the massiveDeccan Trapseruptions that occurred around the same time, andclimate change, checking against thefossilrecord. However, on March 4, 2010, a panel of 41 scientists agreed that the Chicxulub asteroid impact triggered the mass extinction.[49]

One item that may not have have been considered is that the Deccan Traps are approximately on the other side of the world from the Chicxulub impact site and that the shock wave from the impact in the Yucatan probablycaused could have caused the eruptions in India.

Because of its magnitude, scientists have speculated that the gases released during the formation of the Deccan Traps played a role in the Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary or K-T extinction).[7] It has been theorized that sudden cooling due to sulfurous volcanic gases released by the formation of the traps and toxic gas emissions may have contributed significantly to the K–Pg, as well as other, mass extinctions.[8] However, the most popular current consensus among the scientific community is that the extinction was triggered by the Chicxulub impact event in North America (which would have produced a sunlight-blocking dust cloud that killed much of the plant life and reduced global temperature, called an impact winter).[9]

Work published in 2014 by geologist Gerta Keller and others on the timing of the Deccan volcanism suggests the extinction may have been caused by both the volcanism and the impact event.[10][11] This was followed by a similar study in 2015.[12][13]

BTW, the Deccan Fields are located at 17 to 24 degrees north latitude, and the Chicxulub crater is located at 21 degrees north latitude.

Thank you, fahrquad, for all this great information. I have just one question. I am thinking of it and asking because of something I read just recently. Turn on your imagination because I am not sure I can describe it rightly.

You said "BTW, the Deccan Fields are located at 17 to 24 degrees north latitude, and the Chicxulub crater is located at 21 degrees north latitude."

What I had read was something like the tilt of Earth can cause what happens at a lower latitude to carry across through the upper atmosphere to affect another place that is at a higher latitude. If I describe that rightly, I presume the same would work the opposite way in the southern hemisphere. Anyway, if you understand what I am describing, is it possible that what happened at Chicxulub could have affected areas even further north or south because of the tilt of Earth - say Siberia or Tasmania? The fallout from the collision could rise into a higher atmosphere, travel toward Eurasia and fall back on a far different latitude.

Thank you, fahrquad, for all this great information. I have just one question. I am thinking of it and asking because of something I read just recently. Turn on your imagination because I am not sure I can describe it rightly.

You said "BTW, the Deccan Fields are located at 17 to 24 degrees north latitude, and the Chicxulub crater is located at 21 degrees north latitude."

What I had read was something like the tilt of Earth can cause what happens at a lower latitude to carry across through the upper atmosphere to affect another place that is at a higher latitude. If I describe that rightly, I presume the same would work the opposite way in the southern hemisphere. Anyway, if you understand what I am describing, is it possible that what happened at Chicxulub could have affected areas even further north or south because of the tilt of Earth - say Siberia or Tasmania? The fallout from the collision could rise into a higher atmosphere, travel toward Eurasia and fall back on a far different latitude.

Comment?

Debris from the impact traveled through the upper atmosphere and rained down all over the globe and has been found in soil samples at the KT boundary.

Imagine the Earth as a giant droplet of water and the asteroid as a grain of sand. Now imagine the grain of sand hitting the droplet at the upper portion of the droplet and surface of the droplet rippling until the motion stabilizes. The majority of the motion would have been in the upper part of the droplet although the lower part would have had some degree of motion. Remember that the Earth is liquid like a water droplet and is covered with a thin shell like the water tension in a water droplet.

Debris from the impact traveled through the upper atmosphere and rained down all over the globe and has been found in soil samples at the KT boundary.

Imagine the Earth as a giant droplet of water and the asteroid as a grain of sand. Now imagine the grain of sand hitting the droplet at the upper portion of the droplet and surface of the droplet rippling until the motion stabilizes. The majority of the motion would have been in the upper part of the droplet although the lower part would have had some degree of motion. Remember that the Earth is liquid like a water droplet and is covered with a thin shell like the water tension in a water droplet.

Ah! Earth is not flat? <G> Seriously, thank you. That explains it. The debris didn't rise straight up - or, even if it did - the debris falling to the curved surface spread it all over. So, what I had read (and described above) must have been about something else.

I must check volcanic ash. There is quite a story about one such explosion. Again, thank you.

Why:The cause of the End-Cretaceous extinction remains hotly debated. No one disputes that a chunk of space rock slammed into the planet near Mexico’s Yucatan Peninsula at the time. But researchers disagree on whether the asteroid strike caused or merely contributed to the die-off. Large-scale volcanic activity in India’s Deccan Traps was already underway before the impact, and aScience Advancesstudy published in February suggests both the asteroid hit and Deccan Traps activity coincided with a general uptick in planetwide volcanism. Whatever the catalyst, it appears a spike in carbon dioxide and a drop in ocean oxygen levels were followed by a rapid post-asteroid cooling.

There is no surface water on the Yucatan Peninsula because all of the rock strata was fractured by the Chixculub impact, so the water flows underground. Occasionally the limestone roof of an underground cavern collapses forming a cenote (sen-no-TAY).

We visited the "Sacred Cenote" at Chichen Itza (above). Not my photo. Still haven't downloaded the flashcards to the external hard drive.

Thank you. Two things strike me. One is the constant changing of our climate. Ignoring for the moment the causes, we rotate from global warming to global cooling over and over. Now it is happening again and we are demanding of ourselves that we put a stop to it. As George Will (editorialist) once said: "It has happened before; it will happen again."

Second, it is reminding me of the last chapter of Bill Bryant's "A Short History of Nearly Everything". A chapter well worth reading and pondering. I would not say he is totally right but he certainly makes the point of man's responsibility in many an extinction. Like our war on "invasive species".

That was a good article, though. Some pretty fierce-looking creatures lived back then.

Thank you. Two things strike me. One is the constant changing of our climate. Ignoring for the moment the causes, we rotate from global warming to global cooling over and over. Now it is happening again and we are demanding of ourselves that we put a stop to it. As George Will (editorialist) once said: "It has happened before; it will happen again."

Second, it is reminding me of the last chapter of Bill Bryant's "A Short History of Nearly Everything". A chapter well worth reading and pondering. I would not say he is totally right but he certainly makes the point of man's responsibility in many an extinction. Like our war on "invasive species".

That was a good article, though. Some pretty fierce-looking creatures lived back then.

Woolly Mammoths, Giant Sloths, Cave Bears, and Sabre Tooth Tigers were pretty fearsome looking too, at least until we "killed them to death". Species will come and species will go, but life in whatever form will still go on here on Earth (until the sun goes nova). Whether that includes humans remains to be seen.